different NIQE with Matlab

[greatlog]

Thanks for your awesome work.

I find some problems when I use pyiqa to calculate the NIQE score. It seems the result calculated by pyiqa is different from that of Matlab.

import matlab.engine
import matlab

import torch
import pyiqa

im = cv2.imread("img.png")


## calculate via matlab
eng = matlab.engine.start_matlab()
im_m = matlab.uint8(im.tolist())
niqe_matlab = eng.niqe(im_m)

## calculate via pyiqa
im_t = torch.FloatTensor(im.transpose(2,0,1)[None]).cuda() / 255.0
niqe_fn = pyiqa.create_metric("niqe")
niqe_pyiqa = niqe_fn(im_t)

[chaofengc]

Please note that we use the official codes and parameters here rather than the default function in matlab.

[greatlog]

So the default function in Matlab is different from the official one.

I get it.

Thanks.

[chaofengc]

Yes, NIQE has some parameters to learn. To ensure consistent behavior, we use the official parameters. And we did not get the default parameters used in matlab either.